CAPI: Silence lockdep warning on get_capi_appl_by_nr usage
As long as we hold capi_controller_lock, we can safely access
capi_applications without RCU protection as no one can modify the
application list underneath us. Introduce an RCU-free
__get_capi_appl_by_nr for this purpose. This silences lockdep warnings
on suspicious rcu_dereference usage.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c
index b054494..3acf94c 100644
--- a/drivers/isdn/capi/kcapi.c
+++ b/drivers/isdn/capi/kcapi.c
@@ -98,6 +98,16 @@
return capi_controller[contr - 1];
}
+static inline struct capi20_appl *__get_capi_appl_by_nr(u16 applid)
+{
+ lockdep_assert_held(&capi_controller_lock);
+
+ if (applid - 1 >= CAPI_MAXAPPL)
+ return NULL;
+
+ return capi_applications[applid - 1];
+}
+
static inline struct capi20_appl *get_capi_appl_by_nr(u16 applid)
{
if (applid - 1 >= CAPI_MAXAPPL)
@@ -185,10 +195,9 @@
ctr->state = CAPI_CTR_RUNNING;
for (applid = 1; applid <= CAPI_MAXAPPL; applid++) {
- ap = get_capi_appl_by_nr(applid);
- if (!ap)
- continue;
- register_appl(ctr, applid, &ap->rparam);
+ ap = __get_capi_appl_by_nr(applid);
+ if (ap)
+ register_appl(ctr, applid, &ap->rparam);
}
wake_up_interruptible_all(&ctr->state_wait_queue);
@@ -215,7 +224,7 @@
memset(ctr->serial, 0, sizeof(ctr->serial));
for (applid = 1; applid <= CAPI_MAXAPPL; applid++) {
- ap = get_capi_appl_by_nr(applid);
+ ap = __get_capi_appl_by_nr(applid);
if (ap)
capi_ctr_put(ctr);
}